Revision 1229e46d3cfe61ee0b11f08fbbc7530af1578637 authored by Peter Maydell on 16 October 2018, 17:09:38 UTC, committed by Kevin Wolf on 05 November 2018, 14:09:54 UTC
Taking the address of a field in a packed struct is a bad idea, because
it might not be actually aligned enough for that pointer type (and
thus cause a crash on dereference on some host architectures). Newer
versions of clang warn about this. Avoid the bug by not using the
"modify in place" byte swapping functions.

There are a few places where the in-place swap function is
used on something other than a packed struct field; we convert
those anyway, for consistency.

Patch produced with scripts/coccinelle/inplace-byteswaps.cocci.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
1 parent c317b64
Raw File
memory_ldst.inc.c
/*
 *  Physical memory access templates
 *
 *  Copyright (c) 2003 Fabrice Bellard
 *  Copyright (c) 2015 Linaro, Inc.
 *  Copyright (c) 2016 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 */

/* warning: addr must be aligned */
static inline uint32_t glue(address_space_ldl_internal, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result,
    enum device_endian endian)
{
    uint8_t *ptr;
    uint64_t val;
    MemoryRegion *mr;
    hwaddr l = 4;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, false, attrs);
    if (l < 4 || !memory_access_is_direct(mr, false)) {
        release_lock |= prepare_mmio_access(mr);

        /* I/O case */
        r = memory_region_dispatch_read(mr, addr1, &val, 4, attrs);
#if defined(TARGET_WORDS_BIGENDIAN)
        if (endian == DEVICE_LITTLE_ENDIAN) {
            val = bswap32(val);
        }
#else
        if (endian == DEVICE_BIG_ENDIAN) {
            val = bswap32(val);
        }
#endif
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        switch (endian) {
        case DEVICE_LITTLE_ENDIAN:
            val = ldl_le_p(ptr);
            break;
        case DEVICE_BIG_ENDIAN:
            val = ldl_be_p(ptr);
            break;
        default:
            val = ldl_p(ptr);
            break;
        }
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
    return val;
}

uint32_t glue(address_space_ldl, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_ldl_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                    DEVICE_NATIVE_ENDIAN);
}

uint32_t glue(address_space_ldl_le, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_ldl_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                    DEVICE_LITTLE_ENDIAN);
}

uint32_t glue(address_space_ldl_be, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_ldl_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                    DEVICE_BIG_ENDIAN);
}

/* warning: addr must be aligned */
static inline uint64_t glue(address_space_ldq_internal, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result,
    enum device_endian endian)
{
    uint8_t *ptr;
    uint64_t val;
    MemoryRegion *mr;
    hwaddr l = 8;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, false, attrs);
    if (l < 8 || !memory_access_is_direct(mr, false)) {
        release_lock |= prepare_mmio_access(mr);

        /* I/O case */
        r = memory_region_dispatch_read(mr, addr1, &val, 8, attrs);
#if defined(TARGET_WORDS_BIGENDIAN)
        if (endian == DEVICE_LITTLE_ENDIAN) {
            val = bswap64(val);
        }
#else
        if (endian == DEVICE_BIG_ENDIAN) {
            val = bswap64(val);
        }
#endif
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        switch (endian) {
        case DEVICE_LITTLE_ENDIAN:
            val = ldq_le_p(ptr);
            break;
        case DEVICE_BIG_ENDIAN:
            val = ldq_be_p(ptr);
            break;
        default:
            val = ldq_p(ptr);
            break;
        }
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
    return val;
}

uint64_t glue(address_space_ldq, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_ldq_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                    DEVICE_NATIVE_ENDIAN);
}

uint64_t glue(address_space_ldq_le, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_ldq_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                    DEVICE_LITTLE_ENDIAN);
}

uint64_t glue(address_space_ldq_be, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_ldq_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                    DEVICE_BIG_ENDIAN);
}

uint32_t glue(address_space_ldub, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    uint8_t *ptr;
    uint64_t val;
    MemoryRegion *mr;
    hwaddr l = 1;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, false, attrs);
    if (!memory_access_is_direct(mr, false)) {
        release_lock |= prepare_mmio_access(mr);

        /* I/O case */
        r = memory_region_dispatch_read(mr, addr1, &val, 1, attrs);
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        val = ldub_p(ptr);
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
    return val;
}

/* warning: addr must be aligned */
static inline uint32_t glue(address_space_lduw_internal, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result,
    enum device_endian endian)
{
    uint8_t *ptr;
    uint64_t val;
    MemoryRegion *mr;
    hwaddr l = 2;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, false, attrs);
    if (l < 2 || !memory_access_is_direct(mr, false)) {
        release_lock |= prepare_mmio_access(mr);

        /* I/O case */
        r = memory_region_dispatch_read(mr, addr1, &val, 2, attrs);
#if defined(TARGET_WORDS_BIGENDIAN)
        if (endian == DEVICE_LITTLE_ENDIAN) {
            val = bswap16(val);
        }
#else
        if (endian == DEVICE_BIG_ENDIAN) {
            val = bswap16(val);
        }
#endif
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        switch (endian) {
        case DEVICE_LITTLE_ENDIAN:
            val = lduw_le_p(ptr);
            break;
        case DEVICE_BIG_ENDIAN:
            val = lduw_be_p(ptr);
            break;
        default:
            val = lduw_p(ptr);
            break;
        }
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
    return val;
}

uint32_t glue(address_space_lduw, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_lduw_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                     DEVICE_NATIVE_ENDIAN);
}

uint32_t glue(address_space_lduw_le, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_lduw_internal, SUFFIX)(ARG1, addr, attrs, result,
                                                     DEVICE_LITTLE_ENDIAN);
}

uint32_t glue(address_space_lduw_be, SUFFIX)(ARG1_DECL,
    hwaddr addr, MemTxAttrs attrs, MemTxResult *result)
{
    return glue(address_space_lduw_internal, SUFFIX)(ARG1, addr, attrs, result,
                                       DEVICE_BIG_ENDIAN);
}

/* warning: addr must be aligned. The ram page is not masked as dirty
   and the code inside is not invalidated. It is useful if the dirty
   bits are used to track modified PTEs */
void glue(address_space_stl_notdirty, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    uint8_t *ptr;
    MemoryRegion *mr;
    hwaddr l = 4;
    hwaddr addr1;
    MemTxResult r;
    uint8_t dirty_log_mask;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, true, attrs);
    if (l < 4 || !memory_access_is_direct(mr, true)) {
        release_lock |= prepare_mmio_access(mr);

        r = memory_region_dispatch_write(mr, addr1, val, 4, attrs);
    } else {
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        stl_p(ptr, val);

        dirty_log_mask = memory_region_get_dirty_log_mask(mr);
        dirty_log_mask &= ~(1 << DIRTY_MEMORY_CODE);
        cpu_physical_memory_set_dirty_range(memory_region_get_ram_addr(mr) + addr,
                                            4, dirty_log_mask);
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
}

/* warning: addr must be aligned */
static inline void glue(address_space_stl_internal, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs,
    MemTxResult *result, enum device_endian endian)
{
    uint8_t *ptr;
    MemoryRegion *mr;
    hwaddr l = 4;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, true, attrs);
    if (l < 4 || !memory_access_is_direct(mr, true)) {
        release_lock |= prepare_mmio_access(mr);

#if defined(TARGET_WORDS_BIGENDIAN)
        if (endian == DEVICE_LITTLE_ENDIAN) {
            val = bswap32(val);
        }
#else
        if (endian == DEVICE_BIG_ENDIAN) {
            val = bswap32(val);
        }
#endif
        r = memory_region_dispatch_write(mr, addr1, val, 4, attrs);
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        switch (endian) {
        case DEVICE_LITTLE_ENDIAN:
            stl_le_p(ptr, val);
            break;
        case DEVICE_BIG_ENDIAN:
            stl_be_p(ptr, val);
            break;
        default:
            stl_p(ptr, val);
            break;
        }
        invalidate_and_set_dirty(mr, addr1, 4);
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
}

void glue(address_space_stl, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stl_internal, SUFFIX)(ARG1, addr, val, attrs,
                                             result, DEVICE_NATIVE_ENDIAN);
}

void glue(address_space_stl_le, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stl_internal, SUFFIX)(ARG1, addr, val, attrs,
                                             result, DEVICE_LITTLE_ENDIAN);
}

void glue(address_space_stl_be, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stl_internal, SUFFIX)(ARG1, addr, val, attrs,
                                             result, DEVICE_BIG_ENDIAN);
}

void glue(address_space_stb, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    uint8_t *ptr;
    MemoryRegion *mr;
    hwaddr l = 1;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, true, attrs);
    if (!memory_access_is_direct(mr, true)) {
        release_lock |= prepare_mmio_access(mr);
        r = memory_region_dispatch_write(mr, addr1, val, 1, attrs);
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        stb_p(ptr, val);
        invalidate_and_set_dirty(mr, addr1, 1);
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
}

/* warning: addr must be aligned */
static inline void glue(address_space_stw_internal, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs,
    MemTxResult *result, enum device_endian endian)
{
    uint8_t *ptr;
    MemoryRegion *mr;
    hwaddr l = 2;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, true, attrs);
    if (l < 2 || !memory_access_is_direct(mr, true)) {
        release_lock |= prepare_mmio_access(mr);

#if defined(TARGET_WORDS_BIGENDIAN)
        if (endian == DEVICE_LITTLE_ENDIAN) {
            val = bswap16(val);
        }
#else
        if (endian == DEVICE_BIG_ENDIAN) {
            val = bswap16(val);
        }
#endif
        r = memory_region_dispatch_write(mr, addr1, val, 2, attrs);
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        switch (endian) {
        case DEVICE_LITTLE_ENDIAN:
            stw_le_p(ptr, val);
            break;
        case DEVICE_BIG_ENDIAN:
            stw_be_p(ptr, val);
            break;
        default:
            stw_p(ptr, val);
            break;
        }
        invalidate_and_set_dirty(mr, addr1, 2);
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
}

void glue(address_space_stw, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stw_internal, SUFFIX)(ARG1, addr, val, attrs, result,
                                             DEVICE_NATIVE_ENDIAN);
}

void glue(address_space_stw_le, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stw_internal, SUFFIX)(ARG1, addr, val, attrs, result,
                                             DEVICE_LITTLE_ENDIAN);
}

void glue(address_space_stw_be, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint32_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stw_internal, SUFFIX)(ARG1, addr, val, attrs, result,
                               DEVICE_BIG_ENDIAN);
}

static void glue(address_space_stq_internal, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint64_t val, MemTxAttrs attrs,
    MemTxResult *result, enum device_endian endian)
{
    uint8_t *ptr;
    MemoryRegion *mr;
    hwaddr l = 8;
    hwaddr addr1;
    MemTxResult r;
    bool release_lock = false;

    RCU_READ_LOCK();
    mr = TRANSLATE(addr, &addr1, &l, true, attrs);
    if (l < 8 || !memory_access_is_direct(mr, true)) {
        release_lock |= prepare_mmio_access(mr);

#if defined(TARGET_WORDS_BIGENDIAN)
        if (endian == DEVICE_LITTLE_ENDIAN) {
            val = bswap64(val);
        }
#else
        if (endian == DEVICE_BIG_ENDIAN) {
            val = bswap64(val);
        }
#endif
        r = memory_region_dispatch_write(mr, addr1, val, 8, attrs);
    } else {
        /* RAM case */
        ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
        switch (endian) {
        case DEVICE_LITTLE_ENDIAN:
            stq_le_p(ptr, val);
            break;
        case DEVICE_BIG_ENDIAN:
            stq_be_p(ptr, val);
            break;
        default:
            stq_p(ptr, val);
            break;
        }
        invalidate_and_set_dirty(mr, addr1, 8);
        r = MEMTX_OK;
    }
    if (result) {
        *result = r;
    }
    if (release_lock) {
        qemu_mutex_unlock_iothread();
    }
    RCU_READ_UNLOCK();
}

void glue(address_space_stq, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint64_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stq_internal, SUFFIX)(ARG1, addr, val, attrs, result,
                                             DEVICE_NATIVE_ENDIAN);
}

void glue(address_space_stq_le, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint64_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stq_internal, SUFFIX)(ARG1, addr, val, attrs, result,
                                             DEVICE_LITTLE_ENDIAN);
}

void glue(address_space_stq_be, SUFFIX)(ARG1_DECL,
    hwaddr addr, uint64_t val, MemTxAttrs attrs, MemTxResult *result)
{
    glue(address_space_stq_internal, SUFFIX)(ARG1, addr, val, attrs, result,
                                             DEVICE_BIG_ENDIAN);
}

#undef ARG1_DECL
#undef ARG1
#undef SUFFIX
#undef TRANSLATE
#undef RCU_READ_LOCK
#undef RCU_READ_UNLOCK
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